1. Field
The present disclosure relates to methods of inspecting manufacturing semiconductor wafers.
2. Brief Description of the Related Art
Miniaturized devices, such as semiconductor devices, are manufactured by applying a plurality of processing steps to a semiconductor wafer. The processing may include a film forming processing to provide a resist layer on the wafer, an exposure processing to expose portions of the resist, a post-exposure bake processing, a development processing, an etching processing to etch exposed or non-exposed portions of the resist, a deposition processing to deposit material at exposed or non-exposed portions of the resist, and other suitable processings. The processings are controlled using suitable processing parameters, such as temperatures, concentrations, exposure doses and other settings. In view of a high throughput of the manufacture it is necessary to control each of the processings based on corresponding parameters such that a desired result is achieved at each processing. Inspection of the semiconductor wafer can be performed after one or more of the applied processings. Based on an inspection result it is possible to adjust one or more of the processing parameters.
The inspection can be performed using suitable inspection tools to measure various properties of the semiconductor wafer and of microstructures formed thereon. Some inspection tools use particle beams or light beams directed to the wafer in order to generate images of the wafer which can be further analyzed to confirm that the processing is performed as desired or to determine defects in the processed wafer. Inspection tools are generally divided into micro-inspection tools and macro-inspection tools.
Micro-inspection tools aim to detect features of very small or even the smallest manufactured microstructures having dimensions of 0.5 μm and below. Micro-inspection tools typically use magnifying optics to detect radiation originating from the inspected location. An advantage of micro-inspection tools is that a geometry or other properties of a microstructure can be directly verified and that deficiencies in these microstructures can be directly shown. A disadvantage of micro-inspection tools is the long time needed for inspection if a substantial portion of the whole surface of the wafer is to be inspected. If only portions of the surface of the wafer are inspected due to time considerations, there is a risk that certain deficiencies are not detected.
Macro-inspection tools aim to achieve a high throughput at the cost of a lower sensitivity to defects and of a lower spatial resolution of the generated images. Macro-inspection tools do not necessarily use magnifying optics to detect radiation emanating from the inspected locations. Macro-inspection tools have an advantage in that large portions of the wafers or the complete wafers can be inspected within a short time, and they have a disadvantage in that the properties of very small manufactured microstructures can not be directly derived from images or other data recorded by the macro-inspection tool.
It is desirable to extend the applicability of macro-inspection tools and micro-inspection tools and to obtain more detailed inspection information from a semiconductor wafer at a high throughput.
It is further desirable to use information obtained using one or more inspection tools in a manufacturing process of semiconductor wafers.